In this paper, non-linear finite elements models (FEM) of steel-timber composite (STC) beams have been developed and analyzed using ABAQUS software. In the FEM, the loading conditions of STC beams were simulated, and the nonlinear behaviour of the contact interface between the steel and timber components were incorporated adequately into the FEM. For the yield load, the maximum error between the FE results and the experimental results is 14.85%. The maximum average error of the yield deflection is 12.94%. and of the ultimate load is 16.79%. However, the error of key points was less than 17% (within a reasonable range), which proves that the established finite element model, selected material parameters and contact element model can better simulate the bending performance of STC beams. Finally, a parametric study was carried out by using the verified FEM. It is shown that the FEM developed in this study can replicate adequately the load-deflection response, and the development of stress and plasticity of the bending experiment. Through the parameter study, it can be seen that the distribution density and mechanical properties of the connection between the glulam and H-section steel can affect the mechanical behavior of the whole STC beams.
This paper aims at investigating the influence of constitution and sound insulation materials on the sound insulation of wood-frame walls. The effects of stud sizes, stud spacing, layers of sheathing and sound insulation materials on the sound insulation were analyzed and discussed. The results showed that the sound insulation property was influenced by layers of sheathing, stud sizes and spacing, density and thickness of sound insulation materials. The regression model was established with six sets of data and five sets of data were used to verify it. The recommended design scheme of wood-frame wall was determined according to the frequency of daily noise.
Steady-state heat transfer performance of wood frame wall is an important index to assess its energy efficiency. In order to study the factors that affect the heat transfer coefficient of wood frame wall, the method of improving the thermal insulation property of the wall was studied. In this paper, 12 wall specimens with different structures were manufactured, and the effective heat transfer coefficient was measured by the hot box-heat flow meter test method. The reliability of the theoretical calculation value of thermal resistance was verified by the experimental value. The results showed that the moisture content of Spruce-pine-fir (SPF), insulation materials, spacing and thickness of studs had influence on the heat transfer coefficient of walls. The effective heat transfer coefficient values of three walls ranged from 0.325 to 0.398 W•m-2•K-1, which met the thermal level It of the severe cold area. The linear correlation between the theoretical calculation value and the test value was up to 0.9587, effective thermal resistance value of wood frame wall can be estimated by calculating without extra experiment.
To improve the surface-finishing performance and enhance the protection of surface coatings, this study employed metallization treatment of fast-growing poplar through an orthogonal experiment. The poplar specimens were impregnated using a low-melting point alloy at different temperatures (75°C, 85°C, 95°C), pressures (0.5MPa, 1 MPa, 1.5 MPa), and times (0.5h, 1h, 2h) to obtain the optimum process parameters and determine the paint film adhesion of metalized poplar. The test results showed that the impregnation effect was obvious with an increase in the pressure and time. The optimum process parameters were 0.5 MPa, 85°C, and 1 h. Contact angle of the treated wood increased, the surface free energy dropped to some extent, wetting property of tread wood decreased. Whether the treated wood or the untreated wood, film adhesion of treated wood got a higher level. After anti-aging treatment, the treated poplar still had a higher level of film adhesion.